[NaCl SDK] Update published version of Visual Studio addin.

The primary change here is to add VS2012 support, but
this also fixes for the default library path as well as
the new location of pnacl toolchain.

R=binji@chromium.org

Review URL: https://codereview.chromium.org/76503002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236576 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236576